Treating phosphates.



cnnrs'rornnn e. 'mnmmmenn.

PHOSPHATE COMPANY, OF NEW YORK,

on i LAKELAND, FLORIDA,

n. Y., A conrona'rron or new YORK.

ASSIGNGE TO COBONET TREATING PHO'SPHATES 1,1925%5. No Drawing.

To all whom it may concern:

Be it known that I, Grrnrs'rornnn G. MEM- MINGER, a citizen of the United States, residing at Lakeland, in the county of Polk and State of Florida, have invented an Improved Process of Treating Phosphates; of which the following is a specification.

I am aware that heretofore various methods have, been employed in the treatment of crude or raw phosphate materials,

by the application of heat and the admixture of alkali bases, to produce a citrate soluble fertilizer. In contradistinction to these methods my present invention relates to the treatment of crude phosphate materials to increase the available percentage of phosphoric acid therein, and which material after treatment may be worked up by any desired process into fertilizers.

I have found in working out my invention or discovery that by the application of intense heat, to certain crude phosphate materials of fr ee silica, the organic matter and the water of combination are first driven oil eliminated, then the calcium carbonate is decomposed into carbon dioxid which passes ed with the other volatile constituents, an

. into calcium oxid which combines with the silica producing calcium silicate in the treated material which replacesthe calcium carbonate in the raw or crude material.- For example the following is an analysis of certain material giving the percentages of the changes in certain constituents thereof both before treatment and after treatment Before After treatment. treatment.

Silica, SiO 7.55% 6.48% (8.10%) Calcium sulfate, CaSO 0. 39% 0.13% Calcium carbonate, (18130 3.55 a 0.00 7 Calcium silicate, CalEliO 0.0 3.39% Organic matter and water of combination 3.53% 0.00%

The material to which my process is applicable also contains a large percentage of combined as tri-basic caland may also contain certain percentages of various other materials such as oxid of iron, oxid of aluminum, and fiuorid of lime. The percentage .of the phosphoric cium phosphate is materially increased by my process, this being the object of my invention; and the percentages of the other named ingredientsnis also materially inphosphoric acid Specification of'Letters Patent.

Application filed December 4,

which contain a sufiicient percentage acid combined as tri-basic cal-v Patented July 25, 191%.

1915. Serial m. 64,958.

creased, although none undergoes any chemical change in the treatment. The increase in the percentages of these ingredients is due merely to the elimination of the organic matter and the water of combination, as well as of other volatile matter if such there be in the crude material. It will also be seen that the percentage (8.10 per cent.) of the silica after treatment includes not only the free silica (6.48 per cent.) but also 1.62 per cent. of silica which 1s combined with the lime, CaO, resulting from the decomposition of the calcium carbonate.

The only material chemical action which takes place in the treatment is therefore,

(la CO l-heat :CaO-l-CO CaO+SiO,-:CaSiO In this as will be understood the treatand merit of the crude or raw materialconslstsin the application of suificient heat thereto of these ingredients to decompose and drive OK the organic mat- This no doubt indicates that approximately two thirds of the calcium sulfur decomposes, the sulfid dioxid being driven elf, while a part of the carbon of the organic matter combines with the surplus oxygen to form carbon dioXid, and the remaining lime com bines with the silica to form calcium silicate. This, however, is only a minor and relatively unimportant reaction.

It will be furthermore understood that the success of the hereinbefore described method of treating crude phosphate material is dependent upon there being a sufficient amountof free silica in the original material to combine with the calcium oxid. I have found by actual tests that if there is a deficiency of silica in the raw material instead of calcium silicate being produced, the elimination of the carbon dioxid merely produces calcium oxid, which, of course, when'exposed to the air forms slaked lime the use of and leaves the material in a very unsatisfactory condition and in which it could not possibly be Worked up into'a fertilizer. It consequently follows, as hereinbefore also stated, that a certain percentage of free silica in the raw or crude material is absolutely necessary to the successful treatment of the material in accordance with this invention. I

When it is understood that in many places phosphates isregulated and determined by the percentage of phosphoric acid therein, and that the material treated by my improved process is sold and shipped in bulk, largely in cargolots, the importance 

